Managing the high-impact load forces is a concern across a number of industries and applications. For instance, absorption of high-impact loads may be particularly applicable in aerospace, industrial power-generation, marine, or other aero-derivative industries, and other industries such as automotive and defense. In the context of aircrafts, it may be useful to plan for one or more element to suffer a high load or impact during flight. Certain elements of the aircraft may be especially susceptible to elevated load conditions that risk damaging the overall aircraft and performance. Accordingly, it may be advantageous to provide an energy-absorbing configuration for these elements.
Within an aircraft, it may be especially useful to minimize damage on or around an engine during flight. Gas turbine engines, such as turbofan gas turbine engine, are often used for powering an aircraft in flight. Some gas turbine engines includes a fan assembly having a plurality of circumferentially spaced apart fan blades, each having a blade root disposed in a complementary, axially extending groove in the perimeter of a rotor disk. As the aircraft is powered during flight, leading portions of the turbofan engine, such as the blades, a casing enclosing the blades or core engine, and/or other propulsive members may encounter extreme loads that are outside the range of loads carried during normal operating conditions.
In the context of fan blades, the normal axial loads carried to the rotor disk by the blade roots are relatively small. During normal operations, these loads include primarily the aerodynamic thrust loads developed by the fan blades, and vibratory loads thereof. However, during operation the engine may be subject to extreme loading conditions. For instance, a blade might strike a bird that is ingested into the engine, or a blade-out occurrence may arise wherein one of the fan blades is severed from the rotor disk. These extreme conditions may generate relatively large axial forces upon impact with adjacent blades. During such conditions, the bird or severed blade is accelerated in the downstream direction by impact with the adjacent blades, which imposes a relatively large force in the axial upstream direction.
In order to accommodate such large axial forces, many conventional systems rely on solid or multi-piece members. For example, in the context of fan blades, solid retainers or retention brackets positioned in front of and/or behind the axial blade root within the axially extending groove. These conventional systems may add significant cost and/or weight to the overall engine. Moreover, during normal use, the additions of weight may negatively impact engine efficiency and performance.
Accordingly, further improvements are desired to increase system performance while reducing cost and weight.